What is the recommended treatment regimen for tuberculosis (TB) in India?

Recommended Treatment Regimen for Tuberculosis in India

The standard recommended treatment for drug-susceptible tuberculosis in India is a 6-month regimen consisting of isoniazid, rifampin, pyrazinamide, and ethambutol daily for 2 months (intensive phase), followed by isoniazid and rifampin for 4 months (continuation phase). 1, 2

First-Line Treatment Algorithm

Initial Phase (2 months):

• Four-drug regimen: Isoniazid (H) + Rifampin (R) + Pyrazinamide (Z) + Ethambutol (E)
• Dosing options:
  • Daily dosing: Preferred for most patients
  • Thrice weekly dosing: Alternative under directly observed therapy (DOT)

Continuation Phase (4 months):

• Two-drug regimen: Isoniazid (H) + Rifampin (R)
• Same dosing frequency as initial phase

Dosage Guidelines

Adults:

• Isoniazid: 5 mg/kg (up to 300 mg) daily; or 15 mg/kg (up to 900 mg) 2-3 times weekly 3
• Rifampin: 10 mg/kg (up to 600 mg) daily
• Pyrazinamide: 20-25 mg/kg daily 4
• Ethambutol: 15-20 mg/kg daily

Children:

• Isoniazid: 10-15 mg/kg (up to 300 mg) daily; or 20-40 mg/kg (up to 900 mg) 2-3 times weekly 3
• Ethambutol should be used with caution in children whose visual acuity cannot be monitored (typically under 6 years) 1

Special Situations

Extended Treatment Duration:

• For patients with cavitary pulmonary TB and positive cultures after 2 months of treatment: extend continuation phase to 7 months (total 9 months) 1, 2
• For extrapulmonary TB: standard 6-month regimen is generally sufficient, but longer treatment (9-12 months) recommended for:
  • Miliary TB
  • Bone/joint TB
  • Tuberculous meningitis 1, 5

HIV Co-infection:

• Same drugs as standard regimen, but treatment duration may need extension based on clinical and bacteriological response 6
• Critical to assess for drug interactions with antiretroviral therapy
• Daily therapy preferred over intermittent dosing for patients with CD4+ count <100 cells/mm3 1

Pregnancy:

• Standard regimen without streptomycin (due to risk of fetal ototoxicity)
• Pyridoxine (10 mg/day) supplementation recommended 6

Drug-Resistant TB Management

Isoniazid-Resistant TB:

• Add a later-generation fluoroquinolone to a 6-month regimen of daily rifampin, ethambutol, and pyrazinamide 1

MDR-TB (Resistant to at least isoniazid and rifampin):

• For patients eligible for shorter regimens, the BPaLM regimen (bedaquiline, pretomanid, linezolid, and moxifloxacin) for 6 months is recommended 1
• Alternative: 9-month all-oral bedaquiline-containing regimen with fluoroquinolone, ethionamide (or linezolid), ethambutol, high-dose isoniazid, pyrazinamide, and clofazimine 1
• Treatment should be individualized based on drug susceptibility testing and managed by specialists 6

Implementation Considerations

Directly Observed Therapy (DOT):

• Strongly recommended to ensure adherence and prevent development of drug resistance 1
• Fixed-dose combinations (FDCs) provide a realistic alternative to minimize selective medication intake 6

Monitoring:

• Monthly clinical evaluations to assess adherence and adverse effects
• Sputum examination at 2 months to evaluate treatment response
• If cultures remain positive after 2 months, extend treatment as indicated above

Common Pitfalls to Avoid

• Inadequate initial regimen: Using fewer than 4 drugs initially when drug resistance cannot be ruled out
• Adding a single drug to a failing regimen: This can lead to further resistance development 1
• Premature discontinuation: Increases risk of relapse and drug resistance
• Inadequate monitoring: Particularly for hepatotoxicity in patients with risk factors
• Overlooking drug interactions: Especially with rifampin-containing regimens

By following these guidelines, clinicians can effectively treat tuberculosis in Indian patients while minimizing the risk of treatment failure and development of drug resistance.